The purposes of this study have been to determine the value of staging laparotomy on evaluating the accuracy of the extent of abdominal disease at the time of initial evaluation and what influence this has on the initial therapy for patients with early stage Hodgkin's disease. 175 patients with Hodgkin's disease have undergone staging laparotomy and splenectomy. This has revealed that the pre-operative assessment of the extent of abdominal involvement was incorrect in approximately 40% of these cases. The prediction of splenic involvement by Hodgkin's disease was incorrect in one-third of the patients and approximately one-third of abnormal lymphangiograms could not be confirmed at laparotomy. A certain number of cases of involvement of nodes in the porta hepatic region outside the usual irradiation therapy ports were discovered. A small number of patients were also found to have documented liver involvement which had not been suspected by pre-operative evaluation. These findings have altered the therapeutic approaches significantly in a number of patients. The results of these studies have been important in the subsequent design of further therapeutic protocols for the treatment of Stages I-A to III-A Hodgkin's disease.